Beaverhead County, the City of Dillon, and the Town of Lima have been working with the Federal Emergency Management Agency (FEMA) and Montana Department of Natural Resources and Conservation (DNRC) to update and produce new floodplain maps for the Beaverhead River, Blacktail Deer Creek, Selway Slough and Junction Creek areas, and the Big Hole River.

Many of the existing floodplain maps are based on data from the late 1970s.  Updated Flood Insurance Rate Maps will provide more accurate, current, and detailed data and mapping of flood risk areas. When finalized, the new maps could have effects on some property owners in mapped floodplains (see Floodplain FAQs page for more information).

View Preliminary Floodplain Maps

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 View individual preliminary maps and reports here: Maps & Technical Reports

Get more information on floodplain designations referenced on the maps:

100-Year Floodplain
Floodway (within the 100-Year Floodplain)
500-Year Floodplain

Newly Mapped into a 100-Year Floodplain on the preliminary maps?  See Low Cost Insurance Options

FEMA will open an official comment and appeal period on the maps (estimated early 2021). More information on the comment and appeal process can be found here (comment and appeal information).  

Big Hole River Floodplain Maps

A flood study and floodplain maps for the Big Hole River were produced in 2015. The Big Hole River floodplain maps and study information have been incorporated into the preliminary FEMA floodplain maps and will go through an official 90 day comment and appeal period along with the rest of Beaverhead County's floodplain maps (estimated early 2021). 

Public Meetings

Stay tuned for updated public meetings in fall 2020.

The County, City and Town hosted two Public Open Houses to help property owners review the initial draft maps.  The meetings were held in Dillon on May 9, 2019 and in Lima on May 13, 2019. 

Come back for more information

We will update this website with new, relevant information as this project progresses.